South Korea says marines are staging artillery firing drills from a front-line island shelled by North Korea last year.
A Defense Ministry official says Wednesday's drills are at Yeonpyeong Island near the disputed western sea line with North Korea.
He says it's South Korea's second live-fire drills from Yeonpyeong since the North's artillery attack in November that was in response to what South Korea claims were routine firing exercises.
The bombardment killed two civilians and two marines and sharply spiked tensions on the peninsula.
The official says South Korea is holding similar drills from nearby Baengnyeong Island on Wednesday.
He spoke on condition of anonymity, citing department rules.